1. Field of the Invention
The present invention relates to a fastener assembly for attaching a carrier to a conveyor chain, said conveyor chain comprising a plurality of link plates and link pins. The carrier is attached to the conveyor chain by means of a fastener.
The present invention also relates to a carrier for use with a fastener assembly of the above-mentioned kind. Such a carrier comprises a main body with a hook arranged to engage with an article to be conveyed.
Finally, the present invention relates to a method for modifying a conveyor chain.
2. Description of the Related Art
It is well known in the art to attach carriers for conveying articles, such as bottles, packages or hangers on racks, to conveyor chains by means of fasteners.
US patent application No. 2005/0077153 A1 discloses a conveyor chain system comprising a carrier, which is attachable to a fastener straddling a conveyor chain. Said conveyor chain comprises a plurality of link plates and link pins connecting said link plates, and said fastener is provided with holes or recesses on both sides for receiving said link pins.
This conveyor chain system is disadvantageous in that the fasteners are difficult to attach and remove, in particular when the chain itself is inaccessible. Furthermore, due to its design, this conveyor chain system can only be used in a limited field of applications.
A similar conveyor chain is disclosed in U.S. Pat. No. 4,271,960. This conveyor chain is provided with a fastener, which has a sleeve portion arranged to receive a pair of link pins for attaching said fastener to said conveyor chain and a carrier portion for engaging with a conveyor belt. This conveyor chain can also be employed to move an article such as a bottle, in which case the fastener acts directly on the bottle. The fasteners are either located in between two opposing link plates, or has spaced apart leg portions arranged to straddle said opposing link plates.
This conveyor chain has all the disadvantages associated with the above conveyor chain system. It is especially difficult to attach and remove the fasteners of this conveyor chain when they are located in between two opposing link plates, since this necessitates dismantling of the conveyor chain.
EP 1 048 593 discloses a conveyor chain with, in addition to the standard link plates and link pins, extended link pins, on which are mounted a plurality of fasteners in the form of plates. The fasteners are attached to the link plates on one side of the conveyor chain and a carrier, which may be a hook, is attached to each fastener.
Extended length link pins are also used for the fasteners attached to the conveyor chain disclosed in U.S. Pat. No. 5,857,558.
These conveyor chains are more adaptive than the previous ones. However, to attach the fasteners disclosed in these documents to a standard conveyor chain, the standard length link pins have to be replaced by extended length link pins, a complicated and time-consuming procedure which involves dismantling of said conveyor chain.
Finally, U.S. Pat. No. 5,799,769 discloses a carrier for use with a hanging conveyor system. The carrier has a receiving region with a U-shaped cross section for receiving a hanger hook and a head region arranged to interact with a conveyor. The receiving region contacts the hanger such that the hanger does not twist. The document also discloses methods for automatically loading and unloading the carrier with hangers, e.g. by using ascending and descending racks.
This carrier is designed to minimize swinging motions of hangers, and the document is silent on how to avoid the above-mentioned problems when attaching said carrier to said conveyor chain.
Thus, there is a demand for a fastener for attaching a carrier to a conveyor chain, which fastener is easily attached to and removed from said conveyor chain and which does not impair the functionality of said conveyor chain when mounted thereon.